1. Field of the Invention
The present invention relates to propulsion systems for toys and other novelty items that cause the novelty items to follow a length of track. Furthermore, the present invention relates to propulsion systems for toys that utilize magnetic fields.
2. Prior Art Background
Wheeled toys have been a favorite of children for many centuries. In that time there have been countless models, shapes, styles and sizes of wheeled toys. For many wheeled toys, such as wheeled vehicles, tracks are often created. The tracks allow for one or more wheeled toy to roll freely while being guided by the track. Often the track is little more than an inclined plane having guide rails. The wheeled toy is placed at the top of the inclined plane and is allowed to roll freely to the bottom of the inclined plane. The momentum of the rolling toy can then be used to propel the toy along the floor away from the track.
As the making of toys became industrialized, the tracks used to guide wheeled toys became more sophisticated. Continuous tracks were developed that allowed wheeled toys to travel perpetually within the confines of the track. However, continuous tracks cannot rely upon gravity to make the wheeled toys run along the track. Rather, propulsion systems had to be introduced that would allow the wheeled toys to be moved along the continuous track. There are many types of propulsion systems that have been used to move a wheeled toy, such as a car, along a track. Many of the propulsion systems are contained within the wheeled toy itself. For instance, the wheeled toy may have a wind-up motor or may contain batteries and a motor. In either case, the toy vehicle is self-moving and the track is only used to guide the direction of the wheeled toy as it moves.
In many other applications, the mechanism used to propel a wheeled toy along a track is contained within the track itself. In such applications, the propulsion mechanism must engage the wheeled toy and accelerate the wheeled toy as it passes along the continuous track. Most often, the wheeled toy is engaged by a rotating disk or grabbed by a hook that physically contacts the wheeled toy and propels it along the track. Such prior art propulsion mechanisms are exemplified by U.S. Pat. No. 3,622,158, to Tepper, entitled Racing Toy Having Vehicle Propelling Means.
In some prior art tracks, passive propulsion mechanisms are used to accelerate vehicles along the track. Passive propulsion mechanisms do not physically touch the wheeled toy, but rather propel the wheeled toy with a changing magnetic field. Such prior art propulsion mechanisms are exemplified by U.S. Pat. No. 5,974,977, to Johnson, entitled Magnetic Propulsion Toy System.
A problem associated with most all prior art prolusion mechanisms is that they are large and bulky in proportion to the track being used and the size of the wheeled toy being propelled. Furthermore, prior art propulsion mechanisms can only accelerate the wheeled toys to certain maximum speeds. Any acceleration beyond that speed may cause the wheeled toys fly off the tracks.
A need therefore exists for a wheeled toy and track system where the wheeled toy can be accelerated to great speeds without fear of the wheeled toy leaving the track. A need also exists for a propulsion mechanism for a wheeled toy that moves the wheeled toy along a track in an extremely space efficient manner. These needs are met by the present invention as described and claimed below.